Fig. 1

Systolic blood pressure (SBP) changes during the 10-minute NLT. Baseline blood pressure was measured while participants rested supine, then every minute upon standing for the 10-minute NLT. SBP was not significantly different between the three groups. However, the SBP for > 10 ME/CFS patients was higher than < 4 ME/CFS and HCs and remained high for the duration of the 10-minute NLT